Deep sky observing report (2009 Feb 27/28)

posted: 3129 days ago, on Monday, 2009 Mar 02 at 21:17
tags: astronomy, deep sky, observing report, Sutherland.

Observer: Auke Slotegraaf

Deep sky observing logbook for Thursday/Friday, 2009 February 27/28.

All observations were made with a 12-inch f/4.9 Dobsonian, "Bertha".

Photos of the Sutherland trip are in the Picasa gallery.

HS 397A

Obvious feature in the field of view even at low power. Looks like two faint stars (oriented SW-NE) wrapped in dim nebulosity. At higher power (300x), the south-western star has two dim companions making a compact triangle. The nebulous extent is uncertain or imagined. Lies close north-east of Tarantula. (MSA 495)

NGC 2100

Bright knot of stars. Prominent in 21' field of view. Curious appearance: looks like a small globular cluster overlaid with a coarse open cluster. Diameter 2.3 arcminutes. I see what looks like a small globular cluster, growing much brighter to the middle. Widely scattered over and around it is a coarse open cluster of 30 vF and vvF stars. Lies close north-east of Tarantula. (MSA 495)

Anon

Roughly midway between NGC 2093 and HS 397A, lies a nebulous star. Noted repeatedly while star-hopping. No further description made. Not marked on the Millenium Star Atlas chart 495.

An image by Gendler shows at this position a mB star with annular nebulosity 0.7' across.

NGC 2093

Triangular wedge of mottled light, pointing west-southwest. This nebulous isosceles triangle, 1.6' x 1.2', has its brightest star at the apex. At least 7 other stars are involved, with moderately faint nebulosity about. (MSA 495)

NGC 2108

Moderately faint, starless, round glow, 0.8' diameter. The light is evenly distributed with no brightening to the middle. Like a delicate, distant globular cluster. A beautiful and gentle little thing. (MSA 495)

Pismis 10

One degree west of orange lambda Velorum. A single 11th magnitude star is all that's seen here, at all powers (47x-300x). (MSA 944)

Cl VDBH 56, "The Amphitheatre"

aka BH 56, vdB-Ha 56.

In a low-power (60x, 48') field around this position I see three or four clumps of pretty bright stars, widely separated, often making little triangles.

At the western edge of the field is the most prominent asterism: four bright stars in a capital-L shape, collared by four mF stars in a second tier. The ensemble measures 5' x 2.7' containing 13 stars. The "stage" in this amphitheatre of stars lies to the northwest of the brightest member, which is an unequal double star (HD 76838, V=7.4).

NGC 2671, "The Mini Beehive"

A delightful soft cloud of tiny star-points. At least 25 very very faint stars can be seen in a 4' area, pretty evenly concentrated, so that they make a distinct grouping. Moderately bright stars, totally unrelated, are scattered beyond its borders. The whole strongly recalls the Praesepe cool! (MSA 944)

SL 4

Scanned the area with 60' and 47' fields; here is an extremely large irregular region, murky in appearance, with no obvious definable borders. (MSA 944)
a.k.a. Dcld 263.2+01.6.

Trumpler 10

With the sweeper eyepiece (47x, 60' fov) its hard to know where to look for this cluster. I see a very large area of bright stars, spanning the one-degree field, loosely scattered. Not impressive. Its far more obvious in the 9x50 finder. (MSA 944)

NGC 2792

A very small, moderately bright, grey circle. Not much detail is visible in this planetary, which appears as an evenly illuminated, round, 0.3' disk, edges quite sharply terminated. At times, it is apparently oval, but direction uncertain. Rather disappointing, really! (MSA 944)

eta Carinae

Just before packing up, I took a look at eta Car and the Homunculus. The seeing was very good with crisp, steady, images. The south-eastern lobe is, as usual, brighter and larger than the north-western one. However, the NW lobe appeared larger than I have seen it before, and the dark marking on the SE lobe was more distinct. As noted on 2009 Jan 23/24, the SE lobe has a little bulge, immediately SW of eta Car.

But more intriguingly, it was very clear that the NW lobe is not a regular petal-shape as seen on all previous occasions. Now, I see a prominent gap in its outline, north of eta, creating a short jet or tendril of orange nebulosity, quite apart from the main lobe. This gap/tendril was repeatedly seen through several eyepiece changes. Previously, it seemed as if there was just a slight marking on the NW lobe (a less obvious version of the dark mark on the SE lobe), but tonight the impression of a gap is very strong.

MCG 6-20-4

aka ESO 314-2, MCG-06-20-004, LEDA 25167.

Nothing is seen here with the 32mm (47x, 60' fov), but the little galaxy is plain with 10mm (150x, 17'). It is clearly elongated (0.7'x0.4', ENE-WSW) and isn't much brighter to the middle. South and west-southwest of the galaxy lie a pair of stars (the galaxy fits 2.5 times into their separation). The WSW star is a fine double. Would have been bright enough for John Herschel to pick up. (sketch) (MSA 944)

LEDA lists the galaxy as being only slightly elongated (1:1.13) while I saw it as distinctly elongated. A 2MASS image shows two small stars, in a line, embedded within the galaxy, which may account for its elongated appearance.

nothing more to see. please move along.